Chromecast audiogroup has an "elected leader" and it keeps changing

Thank you for that - I can’t believe I didn’t think of doing that so much earlier!
I’ve modified mine for the 4 (at the moment) Google Homes around the house.

how is it?.. is it working as expected?

This is a smart solution, quickly tested it and it seems to work as expected (i’m on OH3). I am now going to understand how to solve my situation: I want to have a chromecast audio group as a default audio sink in openHAB, so to use say command to give alerts about specific events. Changing in the rule the default audio sink should be possible using something like:

say("Hello world!", "voicerss:enUS", audio_sink.state.toString)

@Mohammad_Chaaban, thanks for this solution. I have a rule that plays the radio on weekday mornings, and wanted to cast it to my audio group (instead of just the Chromecast in my bedroom). I don’t need to control the audio group from a sitemap, so I just added the status checks into my rules to ensure I cast to the elected leader.